The automatic and semi-automatic rifles such as M16 and AR15 made by Colt Company in the U.S. and their Canadian modifications such as C9 and C7 rifles have an ejection port adjacent to the loading system for ejecting spent shell casings after each firing.
The M16 and C9 rifles are used aboard helicopters and ships. The ejection and spill of the empty shells on to the floor of the aircraft and ship can create hazards, for example the empty shells could get ingested into the aircraft engine. This situation is referred to in flight safety as Foreign Object Damage (FOD).
To resolve the spill-out problems, several shell catchers available in the market were considered and tested on the C9 rifle, but none of them were satisfactory. The problems encountered in using the shell catchers related to the restriction in the handling of the weapon itself, incompatibility of types of attachments, size, weight, and most important, improper flow of the empty shells and blockage of the system.
In one of these devices described in U.S. Pat. No. 5,389,439 the empty shell casing is attached to a support plate or, a latching bracket which fits against one side of the loading handle with a locking mechanism. The empty shell catcher is then fixed in the position adjacent to the discharge port of the firearm. In this device, the empty shells collected in the shell catcher are emptied by detachment of the container from its support.
In another device of a different type the spent shell collector consists of a bag with a bottom opening which is closed by a snap fastener. The bag is attached to the firearm with a bracket which covers the empty shell ejection port.
One major disadvantages of the prior art systems is that, the integrity of the natural ejection pathway of the shells is not considered. The ejected spent shells are forced through a pathway into the empty shell container. As a result clogging of the pathway can occur. Another disadvantage is that the mounting bracket of these systems interfere with the operation of the cocking handle in C9 and C7 rifles.